Flu Season Creeps in Slowly and Quietly

Action Points

Explain to patients that the influenza vaccine is safe and effective in preventing the disease and -- because it is a killed vaccine -- cannot infect anyone with flu.

Urge all patients -- but especially those in the high-risk groups -- to get a flu shot.

Note that next week is National Influenza Vaccination Week -- as designated by the CDC.

Explain to patients who ask that the FDA last week warned that Tamiflu (oseltamivir), used to prevent or lessen the effect of an influenza infection, has been associated with cases of abnormal behavior among children and required that a warning be placed on the drug's label.

ATLANTA, Nov. 22 -- The seasonal flu season is here, but tell that to the viruses. The quixotic little pathogens haven't yet flexed their muscles in earnest, according to the CDC.

Still, one never knows with flu viruses, so the CDC has designated next week as National Influenza Vaccination Week to emphasize the importance of getting a flu shot.

So far, CDC surveillance shows, only two states -- Alabama and North Carolina -- are reporting regional flu activity, while four others are reporting so-called local activity. The remaining states are reporting sporadic or no flu, according to the CDC's weekly flu report.

"What that map tells you is that it's early in the season," said Joseph Bresee, M.D., chief of the epidemiology and prevention branch of the influenza division of the CDC. But anything can happen over the next few months, he said.

"The mantra is if you've seen one flu season, you've seen one flu season," Dr. Bresee said. Both in its timing and in where it occurs, "influenza is very variable."

A few pediatric cases of flu cropped up in the New Orleans area last month, but "we're not seeing a lot of activity in the adult world," said Sandy Kemmerly, M.D., an infectious diseases specialist with the Ochsner Medical Center there.

"In general, we have a later flu season than the rest of the country," Dr. Kemmerly said, but this year the southeast -- Florida, Louisiana, and Mississippi, as well as Alabama and North Carolina -- has an early lead, while the northeast states and the rest of the nation haven't seen much activity.

The west and south of North Carolina have seen some outbreaks, said Keith Kaye, M.D., of Duke.

"There's a pretty steady flow of cases in certain parts of the state," he said. "We don't have hot activity in Durham, but we know that we will have soon."

The typical flu season peaks in January or February, he said, but it's possible -- and has happened -- for there to be a spike in cases in November, followed by a more normal peak later.

One hint that a November spike may happen in that many of flu strains that have been isolated so far are influenza B, the less common variant. "We might see a spike of B influenza now, and then I wouldn't be surprised to see the more typical A strains later in the winter," he said.

The key to keeping the flu season innocuous is vaccination, and this year there is no shortage of vaccine, Dr. Kemmerly said. "For the first time in many years, we have an adequate supply of vaccine," she said, although some practitioners may still be having trouble getting it.

In fact, according to the CDC, 83 million doses of vaccine had been manufactured and shipped by Nov. 10, and more than 100 million doses are expected to be available this flu season.

On the other hand, without the sense of urgency that a shortage creates, Dr. Kemmerly said, the public may be feeling complacent. "We're not having people clamoring at our doors," she said.

She and Dr. Kaye said the key goal for doctors and their institutions is to persuade as many people as possible to get their shots. "Keep poking that vaccine," Dr. Kemmerly said.

The CDC is urging health-care professionals to target what it calls the high-risk groups -- children between the ages of six months and five years, those older than 65, pregnant women, and those with underlying health disorders that may make them vulnerable to the flu.

The idea of the special flu shot week is to "raise the visibility of influenza vaccination so we do a better job of getting the vaccine into people who need it," the CDC's Dr. Bresee said.

On the other hand, Dr. Kaye said, everybody else can also benefit, unless they're allergic to eggs or have previously had a hyper-sensitivity reaction to a flu vaccine. He added it's important for doctors to counter the "huge misconception" that the vaccine can cause the flu.

While the key form of prophylaxis is vaccination, some people turn to Tamiflu (oseltamivir), which can be used to prevent or lessen the effect of an influenza infection.

The FDA last week warned that the drug has been associated with cases of abnormal behavior among children and required that a warning be placed on the drug's label.

Also, the drug's maker, Roche, sent out a Dear Doctor letter outlining the changes, which arose after more than 100 new cases of delirium, hallucinations, and other unusual psychiatric behaviors were reported in children treated with the drug, mostly in Japan, where it is widely used.

Between 2001 and 2005, Tamiflu was prescribed 24.5 million times in Japan, compared with just 6.5 million in the United States, according to the FDA.

The new warning is "not front-page news," Dr. Kemmerly said, if only because doctors know that Tamiflu chemical cousins -- Symmetrel (amantadine) and Flumadine (rimantadine) -- also have central nervous system effects.

"It's not that huge of a surprise," she said. "I don't think that it will affect anyone's prescribing habits."

Reviewed by Zalman S. Agus, MD Emeritus Professor at the University of Pennsylvania School of Medicine

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